Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.
SACC. 2005 and updates. A classification of the bird species of South America. Available at: https://www.museum.lsu.edu/~Remsen/SACCBaseline.htm.
Critically Endangered | Endangered | Vulnerable |
---|---|---|
- | - | - |
Year | Category | Criteria |
---|---|---|
2023 | Near Threatened | C2a(ii) |
2016 | Near Threatened | C2a(i) |
2012 | Near Threatened | C2a(i) |
2011 | Near Threatened | C2a(i) |
2008 | Near Threatened | C2a(i) |
2004 | Near Threatened | |
2000 | Lower Risk/Near Threatened | |
1994 | Lower Risk/Near Threatened | |
1988 | Near Threatened |
Migratory status | not a migrant | Forest dependency | medium |
Land-mass type |
continent |
Average mass | - |
Estimate | Data quality | |
---|---|---|
Extent of Occurrence (breeding/resident) | 122,000 km2 | medium |
Severely fragmented? | no | - |
Estimate | Data quality | Derivation | Year of estimate | |
---|---|---|---|---|
Population size | 2500-9999 mature individuals | poor | suspected | 2022 |
Population trend | decreasing | poor | suspected | 2016-2027 |
Rate of change over the past 10 years/3 generations (longer of the two periods) | 1-9% | - | - | - |
Rate of change over the future 10 years/3 generations (longer of the two periods) | 10-19% | - | - | - |
Rate of change over the past & future 10 years/3 generations (longer of the two periods) | 10-19% | - | - | - |
Generation length | 3.75 years | - | - | - |
Number of subpopulations | 1 | - | - | - |
Percentage of mature individuals in largest subpopulation | 100% | - | - | - |
Population justification: The global population size has not been quantified. Despite some survey effort in potentially suitable habitat the species is only occasionally recorded, and is assumed to be genuinely rare (Collar and Sharpe 2020, eBird 2022). The population is therefore here tentatively placed in the band 2,500-9,999 mature individuals.
Its inconspicuous and silent habits during the dry season may however lead to it being under-recorded (Collar and Sharpe 2020); an accurate quantification of the population size is urgently required.
Trend justification: There are no data on the population trend, but declines are suspected on the basis of the species' forest dependence and ongoing deforestation in the region.
Over the past three generations (11.3 years), 7% of tree cover has been lost within the range; since 2016 this has been increasing to a rate equivalent to 12% (Global Forest Watch 2022, using Hansen et al. [2013] data and methods disclosed therein). Under the assumption that population declines are roughly equivalent to the rate of tree cover loss, the species is suspected to have declined by 1-9% over the past three generations. With increasing deforestation, population declines are likewise suspected to accelerate, to a rate of 10-19% over three generations into the future.
Country/Territory | Presence | Origin | Resident | Breeding visitor | Non-breeding visitor | Passage migrant |
---|---|---|---|---|---|---|
Bolivia | extant | native | yes |
Country/Territory | IBA Name |
---|
Habitat (level 1) | Habitat (level 2) | Importance | Occurrence |
---|---|---|---|
Forest | Subtropical/Tropical Moist Lowland | major | resident |
Forest | Subtropical/Tropical Swamp | major | resident |
Altitude | 0 - 350 m | Occasional altitudinal limits |
Threat (level 1) | Threat (level 2) | Impact and Stresses | |||||||
---|---|---|---|---|---|---|---|---|---|
Agriculture & aquaculture | Annual & perennial non-timber crops - Agro-industry farming | Timing | Scope | Severity | Impact | ||||
Ongoing | Majority (50-90%) | Slow, Significant Declines | Medium Impact: 6 | ||||||
|
|||||||||
Agriculture & aquaculture | Annual & perennial non-timber crops - Small-holder farming | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
|||||||||
Agriculture & aquaculture | Livestock farming & ranching - Small-holder grazing, ranching or farming | Timing | Scope | Severity | Impact | ||||
Ongoing | Minority (<50%) | Slow, Significant Declines | Low Impact: 5 | ||||||
|
|||||||||
Biological resource use | Logging & wood harvesting - Unintentional effects: (large scale) [harvest] | Timing | Scope | Severity | Impact | ||||
Ongoing | Majority (50-90%) | Slow, Significant Declines | Medium Impact: 6 | ||||||
|
Recommended citation
BirdLife International (2024) Species factsheet: Unicolored Thrush Turdus haplochrous. Downloaded from
https://datazone.birdlife.org/species/factsheet/unicolored-thrush-turdus-haplochrous on 22/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 22/12/2024.